This invention generally relates to an apparatus of the type often referred to as a power rodder. Such constructions usually include means, such as a cage, for storing an elongated section of flexible rod. The rod is adapted to be engaged by driven rolls associated with the apparatus whereby the rod can be extended outwardly to a remote location and then, upon reversal of the drive rolls, retracted back to the apparatus.
Power rodder constructions are typically used for sewer cleaning operations. In such constructions, means are provided for imparting rotary movement to the rod in addition to the extending and retracting movement referred to. Accordingly, the rod can be rotated for more effective movement through obstructions during extending of the rod. In addition, the rotary action permits the use of cutting blades and other implements which further increases the efficiency of cleaning operations.
Power rodders have also been employed in cable placing operations. The rodders may, for example, be used in conjunction with placing of telephone cable wherein the cable is to be located within an underground conduit. When used in cable placing operations it is desirable to know that exact location of the end of the rod so that obstructions or other problems may be quickly located. Also, the distance between conduit access locations can be accurately measured.
It is accordingly an object of the present invention to provide a position detecting apparatus for use in connection wit a power rodder.
In the usual rodding apparatus it is difficult to determine the location of the rod because of the inaccessibility of its end and the fact that the entire assembly rotates making sensing difficult. Further, extremely severe vibration and environmental conditions are encountered. Accordingly, it is another object of the present invention to provide a position detecting apparatus for a power rodder which is capable of indicating the linear quantity of rod which has been dispensed from a rodding device.
A further object of the invention is to provide a position detecting device utilizing a rotational sensor to detect rod movement and transmitting circuits whereby the position of the rod can be received and displayed at a location remote from the apparatus itself.
Another object of the invention is to provide an apparatus for detecting storing and displaying the total quantity of rods expelled and retracted over a considerable period of time so that the wear rate of the rod can be determined.
Still another object of the invention is to provide an apparatus capable of counting the directional rotations of a drive shaft associated with the rod whereby the direction and quantity of rod moved into or out of the machine can be determined.
Other objects and advantages of the invention will be apparent from the remaining portion of the specification.